Hach 3654 Portable H2/N2 Analyzer manual Troubleshooting Operation, Program Identification

3654 Portable H2/N2 Analyzer - Maintenance and Troubleshooting 53 of 66

6.6Troubleshooting - Operation

6.6.1Program Identification

In case of problems, it may be necessary to check the current version of your software as this may be required by Hach Ultra if you need to contact them for assistance in problem solving.

To identify the version of the software in your instrument, switch off the instrument. Then hold down the MEAS button while switching the instrument back on. The instrument will then briefly display the software version number before going through it’s start-up procedures.

6.6.2 Diagnostics Messages

The following are warning messages that may appear on the instrument LCD in place of the gas concentration.

Table 6-1:Diagnostic Messages

Message	Meaning
	This message appears on the LCD if the purge gas supply fails. To detect this
Pur	condition, the voltage signal from the TC sensor is measured. This is normally
	between 1-3 volts, depending which gas is being measured.
	If the flow of purge gas stops, the sensor voltage wanders outside the permitted
	range of 100mV to 4 V. See also “Continuous Purge” below.
Out	This message appears if the sensor is unplugged from its correct position, or if the
	temperature is outside the range -5°C to 100°C.
	During start-up, this message indicates the instrument cannot complete the start-up
	tests successfully (see “Taking Measurements” on page 19). If the problem per-
Err	sists, contact your local Hach Ultra service representative for assistance.
	During calibration, this message indicates that the partial pressure of gas is below
	the acceptable range (<5 mbar), or that you have pressed a wrong key, as
	explained in “Sensor Calibration” on page 36.

6.6.3 Continuous Purge

It may be useful, particularly when seeing a [Pur] error message on your display, to view the purge voltage of the TC sensor in a continuous purge mode. In this mode, there is no purge/measurement cycle, as the purge gas is flowing through the sensor continuously.

To start continuous purge mode, put the instrument into standby, then hold down the Down Arrow button while switching the instrument back on again. The instrument displays [Pur], followed by the purge gas voltage.

At 20-25°C, this voltage should be about 3.00V (± 200 mVolt) for H2/N2 measurements.

To exit from continuous purge mode, put the instrument in standby, then switch back on again without holding any keys.

Operator Manual ORBISPHERE